For billions of years, the gas giant has used its colossal gravity to divert comets and asteroids that could threaten Earth. But its role as a “cosmic vacuum cleaner” is far from simple. Jupiter can also send celestial bodies into the inner Solar System. Here is what we know about the planet that weighs 2.5 times as much as all the other planets combined.

(Staff: Space / Science & Astronomy)

Jupiter is more than just the largest planet in the Solar System. It is a gaseous colossus that, through its mere presence, influences the trajectories of comets and asteroids, shapes the asteroid belt and, according to many scientists, has played an essential role in the history of impacts that have affected Earth. That is why Jupiter is often called the “cosmic shield” of our planet.

How does Jupiter act as a shield?

Jupiter has a mass approximately 318 times greater than Earth’s and a gravity two and a half times stronger than ours. This gigantic force allows it to divert comets coming from the Oort Cloud or asteroids in the belt between Mars and Jupiter. When such a celestial body passes close to Jupiter, its trajectory can change radically: it may be thrown out of the Solar System, captured into an orbit around the planet, or directed towards the Sun.

A famous example is comet Shoemaker-Levy 9, which in 1994 was torn apart by Jupiter’s gravity and then entered its atmosphere, producing spectacular impacts visible from Earth. Without Jupiter, that comet could have reached the inner Solar System, with unpredictable consequences.

But Jupiter is not just a shield

Although the popular image of Jupiter as a protector is attractive, the reality is more nuanced. Recent studies show that Jupiter can also act as a “stardust” that sends some celestial bodies towards Earth. Its gravity can perturb the asteroid belt and alter the orbits of some objects, causing them to enter trajectories that intersect Earth’s orbit. So Jupiter is both a shield and a potential source of danger.

Astonishing figures

• Mass: Jupiter weighs 2.5 times more than all the other planets in the Solar System combined.
• Diameter: It is approximately 11 times larger than Earth.
• Day: A day on Jupiter lasts only 9 hours and 56 minutes, the fastest rotation of all the planets.
• Year: A year on Jupiter lasts 12 Earth years.
• Atmosphere: It is composed mainly of hydrogen and helium, with no solid surface.
• Great Red Spot: A gigantic storm, larger than Earth, that has lasted for at least 350 years.
• Magnetic field: It is approximately 20,000 times stronger than Earth’s.
• Moons: Jupiter has 95 known moons, four of which are famous: Io, Europa, Ganymede and Callisto, discovered by Galileo Galilei in 1610.
• Ganymede is the largest moon in the Solar System, larger than the planet Mercury.
• Europa hides a subsurface ocean of liquid water, considered one of the most promising places for extraterrestrial life.
• Io is the most volcanic body in the Solar System, with hundreds of active volcanoes.

Missions exploring Jupiter

Jupiter has been visited by several space probes: Pioneer 10 and 11, Voyager 1 and 2, Galileo, and currently Juno is studying the planet and its moons. In the future, Europa Clipper (NASA) and JUICE (ESA) will explore Europa and Ganymede in detail, looking for clues about the subsurface ocean and the possibility of life.

Conclusion

Jupiter is a giant of the Solar System, a two-faced guardian: on the one hand, it protects us from numerous comets and asteroids; on the other hand, it can divert some celestial bodies towards us. Regardless of its exact role, Jupiter remains one of the most fascinating planets, a natural laboratory for studying planetary formation, magnetic fields and the possibility of life in the hidden oceans of its moons.